1. Field of the Invention
The present invention relates to an information processing device, an information processing method, and a program, and more particularly to an information processing device, an information processing method, and a program, which enable an agent (autonomous agent) capable of autonomously doing an action to efficiently imitate (copy) an action done by another person which is an object other than the agent.
2. Description of the Related Art
As an agent which can do actions autonomously, there is an agent which learns a learning model such as an HMM (hidden Markov model), and a controller which, for each state transition in the HMM, outputs an action to be done for causing the state transition, using an observed value sequence obtained by sensing environments (for example, refer to Japanese Unexamined Patent Application Publication No. 2009-223444).
In such an agent, a state sequence in which one state reaches another state in the HMM is obtained, and an action causing a state transition in the state sequence is done using a controller.
In addition, a human being can imitate other people except for himself/herself, and the imitation leads the human being to obtain skills or knowledge more efficiently than learning by trial and error without assistance.
As for the imitation for obtaining skills or knowledge or the like, a person doing an imitation (imitator) moves his/her own body such that, for example, a state of the imitator himself/herself becomes a state of another person who is perceived by stimuli (light from another person and the like) received from another person.
That is to say, the imitator moves his/her body such that a state of the imitator himself/herself which is (internally) perceived by the imitator himself/herself matches a state of another person perceived by stimuli received from another person.
It may be thought that when a human being (imitator) imitates another person, the imitator knows, from his/her experiences till then, senses which the imitator is likely to feel when a state of the imitator himself/herself matches a state of another person, and moves his/her body so as to obtain the senses.
Therefore, in order to do an imitation, it is necessary to correlate a state (a state of another person which is visually seen) of another person perceived by stimuli which the imitator receives from another person with senses (a state of the imitator himself/herself which the imitator feels) which the imitator is likely to feel when the state of the imitator himself/herself matches the state of another person perceived by the imitator.
Here, the correlation is also hereinafter referred to as a correlation of a state of an imitator himself/herself with a state of another person.
In order to do an imitation, as a physiological knowledge to support the necessity of the correlation of a state of an imitator himself/herself with a state of another person, there are neurons called a mirror neuron.
For example, there exists a neuron group commonly ignited in the brain when a human being himself/herself does an action (deed) (behavior) of “grasping” and when he/she observes the same action of “grasping” done by another person, and the neuron group is called the mirror neuron.
When an agent is made to imitate an object other than the agent, that is, for example, another agent, it is necessary for the agent which is an imitator to correlate a state of the imitator himself/herself with a state of another person.
However, when the agent is made to imitate an object other than the agent, that is, for example, another agent, it is difficult for the agent which is an imitator to correlate a state of the imitator himself/herself with a state of another person without any condition (assumption).
In other words, when the agent is made to imitate another agent, data indicating a state of another person is observed by the agent which is an imitator (hereinafter, also referred to as “a self agent”) from another agent which is another person (hereinafter, also referred to as “the other agent”). In addition, in the self agent, data indicating a state of the imitator himself/herself is observed from internal movable parts or the like of the self agent.
In the self agent, an observed value measured as data indicating a state of another person and an observed value measured as data indicating a state of an imitator himself/herself will be observed values different in kind (modal).
Specifically, when see-and-copy is done by seeing and copying another person in order to do an imitation, in the self agent, for example, an image obtained by capturing the other agent with a camera is observed as an observed value indicating a state of another person, and angles of movable parts (for example, parts corresponding to joints) of the self agent are observed as observed values indicating a state of the imitator himself/herself (here, a state of a posture).
Since the image of the other agent and the angles of the movable parts of the self agent are observed values which are different in kind, the self agent may not determine whether or not a state of the self agent itself matches a state of the other agent contained in the image taken by the camera through comparison of the angles of the movable parts of the self agent with the image of the other agent. Therefore, it is difficult to learn (obtain) a correlation of a state of the imitator himself/herself with a state of another person, that is, for the self agent to recognize the angle of the movable parts of the self agent itself necessary to match a state of the self agent itself to a state of the other agent contained in the image of the other agent.
In order for the self agent to learn a correlation of a state of the imitator (the self agent) himself/herself with a state of another person (the other agent), it is necessary to set predetermined conditions (hereinafter, also referred to as “correlation conditions”) for correlating a state of the imitator himself/herself with a state of another person to an environment where the learning is carried out.
For example, when the self agent has succeeded in doing a certain action, by designating as the correlation condition that a so-called care giver does the same action as the action in which the self agent has succeeded along with an utterance indicating the action, the self agent can correlate a state of the imitator (the self agent) himself/herself with a state of another person (the care giver).
In other words, for example, when the self agent has succeeded in doing an action of grasping a glass, by the care giver doing the action of grasping a glass along with an utterance of “grasping a glass,” the self agent can correlate a state when the self agent itself does an action of grasping a glass with a state when another person (the care giver) does an action of grasping a glass.
In addition, for example, as senses of a child are prompted to be developed by parents copying actions of the child, the self agent can correlate a state of another person (the care giver) with a state of the imitator (the self agent) himself/herself by designating as the correlation condition that the care giver copies the action done by the self agent with a significance probability.
Further, for example, a mirror is installed in front of the self agent, the correlation condition is to regard the self agent in the mirror as another person, and thereby the self agent may correlate a state of another person (the self agent in the mirror) with a state of the imitator (the self agent) himself/herself. Also, in this case, after the learning of the correlation of a state of the imitator himself/herself with a state of another person has progressed to some degree, the other agent is placed instead of the mirror, and thereby the self agent can imitate the action done by the other agent by using a result of the learning of the correlation of a state of the imitator himself/herself with a state of another person.